Black-and-white photosensitive materials after exposure are processed through a series of steps of development, fixation, washing and the like. These steps are generally carried out in an automatic processor having a series of processing tanks filled with a developer, fixer and other processing solutions by successively conveying a length of photosensitive material through the tanks.
To maintain the processing ability of processing solution in a processor tank constant, such continuous processing often relies on the replenishment mode wherein a replenisher for the processing solution is made up in an amount corresponding to the quantity of photosensitive material processed. In the case of X-ray photosensitive material, for example, the processing solution replenisher is prepared by furnishing a replenisher reservoir having a replenisher concentrate received therein, introducing a predetermined amount of the replenisher concentrate into a stock tank, and adding a predetermined amount of water thereto for dilution.
More particularly, for developers, their replenisher concentrate is available in a one, two or three-part system, each part being received in an individual reservoir. In a system having two or more parts, reservoirs containing the parts are usually combined into an integral reservoir assembly. Similarly for fixers, their replenisher concentrate is available as a one or two-part system, each part being received in an individual reservoir.
At present, environmental maintenance and resource saving are generally the most important requirements in the industry. It is desired to reduce the amount of processing solution and water used. In such situations, as to the processing of photosensitive material in the replenishment mode, it is also desired to reduce the replenishment amount. In practice, the technology tends toward a decreasing replenishment amount.
A reduced replenishment amount will result in a reduced frequency of replacement of a replenisher reservoir. Irrespective of the advantage that the frequency of a replenisher reservoir becoming empty is reduced, replacement of new replenisher reservoirs is rather complicated since the cycle of reservoirs becoming empty varies between a developer and a fixer. There can occur an accident that one reservoir has been replaced, but the other reservoir is left unchanged.